Collaborative Research RUI: Examination of the Effect of Templating Agents on the Size, Shape and Chiral Recognition of Bifurcated Amino Acid Based Amphiphilic Molecular Assemblies

在化学学部大分子、超分子和纳米化学项目的支持下，来自德克萨斯a&m大学科帕斯克里斯蒂分校（TAMUCC）的Eugene Billiot、Fereshteh Billiot和Mark Olson，以及他们在迦太基学院的合作者Kevin Morris，将合成并表征一类新型的“支链”氨基酸表面活性剂。这项研究的目标是了解这些分子聚集和自组装的分子因素，这些分子将与具有生物学重要性的分子相互作用并识别它们。表面活性剂的合成将使用绿色化学方法，其中材料将由氨基酸基起始材料制备，而不是潜在危险的多芳烃。此外，由于表面活性剂是以氨基酸为基础的，因此它们有望具有生物相容性。该研究将有助于填补当前知识库的空白，这对于正确设计和选择更有效的手性选择器至关重要。此外，由于所研究系统的对映体识别是基于氨基酸支架的，因此从这些研究中获得的知识将有可能转移到其他基于氨基酸的系统，如蛋白质。该项目是两所主要本科院校之间的合作，其中一所院校TAMUCC是为西班牙裔服务的机构（HSI）。因此，由该基金资助的研究将作为研究团队招募、培训和指导来自代表性不足和经济困难背景的学生的工具，并鼓励这些学生攻读理科学士学位。研究的重点是调查和阐明负责(a)自组装，(b)功能，(c)高阶结构和(d)氨基酸基大分子组装（AABMAs）的分子识别的因素。将比较“线性”AABMAs与新型“分叉”AABMAs的性质，以及表面活性剂浓度、表面活性剂类型（线性与分叉）、pH和反离子/模板剂类型等因素对AABMAs的大小、形状、物理性质和对映体识别的影响。AABMAs将以其单体和聚合物形式进行研究。暴露于Co60 γ辐射或185 nm真空紫外辐射下，AABMAs胶束会交联。研究了pH、反离子/模板剂和表面活性剂浓度对聚合、自组装、功能、高阶结构和分子识别的影响。将利用核磁共振（NMR）、荧光、小角中子散射（SANS）、小角x射线散射、低温透射电子显微镜、动态光散射方法以及毛细管电泳（CE）等多种技术来进一步了解所形成的AABMAs的物理性质。将进行热力学研究，以深入了解表面活性剂/聚合物胶束的手性分子识别单元与手性分析物之间的结合相互作用，这些分析物将用于使用滴定微热法进行手性分离。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Eugene Billiot, Fereshteh Billiot and Mark Olson of Texas A&M University Corpus Christi (TAMUCC), along with their collaborator Kevin Morris at Carthage College, will synthesize and characterize a novel class of “branched” amino acid-based surfactants. The goal of the research is to understand the molecular factors responsible for the aggregation and self-assembly of these molecules into structures that will interact with and recognize molecules of biological importance. Synthesis of the surfactants will use a green chemistry approach where materials will be prepared from amino acid-based starting materials instead of potentially hazardous polyaromatic hydrocarbons. Furthermore, since the surfactants are amino acid-based, they are expected to be biocompatible. The research will help fill a void in the current knowledge base that is critical for the proper design and selection of more efficient chiral selectors. In addition, since enantiorecognition of the systems under study is based upon amino acid-scaffolding, the knowledge gained from these studies will be potentially transferable to other amino acid-based systems such as proteins. This project is a collaboration between two primarily undergraduate institutions, with one of those two institutions, TAMUCC, being a Hispanic-serving institution (HSI). Thus, the research to be funded by this grant will serve as a tool for the research team to recruit, train, and mentor students from underrepresented and economically challenged backgrounds and to encourage these students to pursue post baccalaureate degrees in science.The research is focused on investigating and elucidating the factors responsible for (a) self-assembly, (b) function, (c) higher ordered structure and (d) molecular recognition of amino acid-based macromolecular assemblies (AABMAs). A comparison of the properties of “linear” AABMAs to novel “bifurcated” AABMAs will be made and how they are affected by factors such as surfactant concentration, surfactant type (linear vs bifurcated), pH, and type of counterion/templating agent affect the size, shape, physical properties, and enantiomeric recognition of AABMAs. The AABMAs will be studied in both their monomeric and polymeric forms. The AABMAs micelles will be crosslinked by exposure to Co60 gamma radiation or 185 nm vacuum UV radiation. The effect of pH, counterion/templating agent, and surfactant concentration on polymerization, self-assembly, function, higher order structure and molecular recognition will be studied. A variety of techniques such as nuclear magnetic resonance (NMR), fluorescence, Small Angle Neutron Scattering (SANS), small angle X-ray scattering, cryo-transmission electron microscopy, dynamic light scattering methods, as well as capillary electrophoresis (CE) will be utilized to learn more about the physical properties of the AABMAs formed. Thermodynamic studies will be conducted to yield insight into the binding interactions between the chiral molecular recognition units of the surfactants/polymer micelles and the chiral analytes that will be targeted for chiral separations using titration microcalorimetry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.